Once again the point has been missed here. There's no questioning that the 50/1.4 is a better lens. Better in what respects and how much better in those respects and is the extra price justified for your purposes, are the questions. If you are on a budget and you want to take the sharpest pssible images, then the 50/1.8 is one of the best value lenses around.

Daniel's points are all valid, except the 'silliness' issue. (That's just plain silly, Daniel ). And I'm not clear what 'harsh highlights" mean. Perhaps you could explain that.

The more expensive lens usually tends to have better performance at maximum aperture, and the 50/1.4 is no exception here. If I were into shallow DoF photography, I'd pay the extra money and get the 50/1.4. However, most 35mm lenses tend to be sharpest at f8 and both these lenses are no exception here. I doubt that the differences at f8 would be noticeable except at 200% enlargement on screen, representing a print size much larger than anyone would be likely to make from the 35mm format.

There's no doubt that the 50/1.8 is ridiculously light. When I picked up mine up from the shop, my first impression was that the lens elements had to be plastic. I was assured they weren't.

But there's an advantage to lightness. This lens is always in my camera bag. It takes up next to no weight and little volume. However, because I've read reports that the lens can get damaged rolling around in a loosley packed bag that might bounce around on rough terrain, I keep it in a small 'bubble wrap' envelope, in the bag. (You seee, I was brought up to take care of my lenses ).

Lastly, when you buy a lens, you should beware of technology lust. I'm sure we all fall into the trap of buying the 'best' when we don't use or even need the best.

A 50mm prime is not the sort of lens I use often for my, mainly, landscape shots. It's very apparent to me, if you can't fill the frame with the conceived composition, then any resolution advantage a prime may have over a zoom is dissipated. My 50/1.8 essentially becomes a portrait lens when I need that. If portraiture with my 20D was my main activity, I'd definitely opt for the 50/1.4.

As it is, I don't need unused capital sitting in my camera bag 95% of the time. Nor am I interested in throwing away good money for the sake of camera/lens appearance, although I can understand that professionals need to impress their clients .

I've been thinking of getting a 50mm 1.8 becuase I shoot a large amount of low light action, and flash isnt always an option.

(...)

So, i guess where I'm heading is this: if I don't stop it down, and I do use it wide open, how will it work for me then? I imagine that I'm not nearly as nit picky as some on this fourm when it comes to somethings, I would rather have a soft shot than no shot at all, but in your opinions will this work well wide open?

That depends on what your low light action is like.

Is it anything like this?

If it is, then shooting with either 50mm at wide open will most likely give you too shallow DOF to work with, unless you really want the overall softness. Stop it down and yank up the sensitivity (ISO setting) instead.

Working wide open (or close to wide open) with the f/1.4 is particularly bad for pool billiards, where the reflecting light results in halos around balls that aren't in focus:

Sorry about the JPEG artifacts, I don't have the originals handy to generate a higher quality version right now.

When that is said, I'd still use the f/1.4, because I can live with the DOF I get at somewhere between f/3 and f/5, and the sharpness, contrast and bokeh of the f/1.4 is superior in the images I've seen.

However, it's likely that I'll bring my 70-200mm f/2.8L IS instead, since I prefer not to shake my pictures to pieces. Pool halls are dark, and of course any kind of flash use will quickly get me thrown out.

One reason I'm going to buy my second 1.8 ==> I dropped mine the other day and it broke. It didn't break because it was plastic, it broke because it fell from 7 feet onto a very hard floor.

Did I feel bad? Nope.

If I had dropped a 1.4 or my 70-200 I would have been sick to my stomach.

I dropped my 50mm f/1.4 on some cement from about 4.5 feet up. Luckfully the hood was mounted on it backwards which absorbed most of the impact and saved it. The rear element poped out but all that was needed was for it to be screwed back in and have the elements re-aligned. $70 in repairs. Pretty darn lucky.

For me it's more than minute. It's a useable and noticeable difference. But again, it's a difference that you would not know existed until you see it first hand, nor can it be measured in a typical situation.

Here is another example I think is a direct result of this effect which could be tested for:

In my work as a retoucher I develop Raw files for several photographers using a good range of different lenses. From time-to-time a subject is photographed wearing a light shirt (think baby-blue, pink or white). (Actually, this is more often than not, I think rich people are color-blind.)

In cases where the images are over-exposed by 1/3 to 1/2 stop, there is a stark difference in the raw data on the highlight end of the histogram between different calibers of lenses.

On cheap lenses (e.g. 28-105 or my copy of the 50 f/1. the shirts appear to clip and detail is lost. Sections of the shirt are a solid blotch of whatever color the shirt is. Although it appears there is solid clipping of the raw data, there really is not. Reducing the exposure slider slightly brings all the data within the histogram with no clipping data. Yet the shirt still appears to clip heavily.

On a higher-quality lens, such as a 24-70L, 70-200L or 50mm f/1.4 this effect is nearly non-existent. In the same situation when the exposure slider is reduced, detail is brought back into the shirt and all is hunky-dory. It isn't until about 1-stop over-exposure that these lenses show the effect but at this point it's due to the actual raw data being clipped.

My only conclusion is that on higher-quality lenses highlights are being handled much more gracefully. Lower-end lenses tend to give up the ghost too rapidly.

How severely and how often you'll encounter the effect depends heavily on the quality of light (not just exposure).

Interesting! Is this effect noticeable at f8 or just the wider apertures where one expects expensive lenses to be better? Next time I'm in Kuala Lumpur I might pick up a 50/2.8 macro which I believe is a notch better than the 50/1.4.

Hmm.. I actually haven't paid that close attention to the aperture. I should. It doesn't seem to be any specific range, although f/4-f/8 is most used.

I think I'll try to remember to mark down the details of the image when I come across them agian. It would be good to nail this down...